Cell migration

distribution of the Listeria monocytogenes ActA protein is required and sufficient to direct actin-based motility. Mol. (1995). The unrelated surface proteins ActA of Listeria monocytogenes and IcsA of Shigella flexneri are sufficient to confer actin-based motility on Listeria innocua and Escherichia coli respectively. Identification of icsA, a plasmid locus of Shigella flexneri that governs bacterial intra-and intercellular spread through interaction with F-actin. Proc. Natl. bacterial actin nucleator protein ActA of Listeria monocytogenes contains multiple binding sites for host microfilament proteins. Curr. (1999). Role of proteins of the Ena/VASP family in actin-based motility of Listeria monocytogenes. The tandem repeat domain in the Listeria monocytogenes ActA protein controls the rate of actin-based motility, the percentage of moving bacteria, and the localization of vasodilator-stimulated phosphoprotein and profilin. (1998). The interaction of Arp2/3 complex with actin: nucleation, high affinity pointed end capping, and formation of branching networks of filaments. (2000). Three regions within ActA promote Arp2/3 complex-mediated actin nucleation and Listeria monocytogenes motility. (1999). The unipolar Shigella surface protein IcsA is targeted directly to the bacterial old pole: IcsP cleavage of IcsA occurs over the entire bacterial surface. Mol. Directed cell migration is an integrated process that is essential for embryonic development and throughout life (Figure 1). The failure of cells to migrate or the migration of cells to inappropriate locations can result in abnormalities or have life-threatening consequences. For example, many congenital defects in brain development leading to mental disorders can be attributed to defects in neuronal migration. In the adult, cell migration is central to homeostatic processes, such as mounting an effective immune response and the repair of injured tissues. Migration can also contribute to some pathological processes, including vascular disease, chronic inflammatory diseases, and tumor formation and metastasis. Thus, there is considerable interest in understanding cell migration on a molecular level because this could lead to novel therapeutic approaches, especially in areas of biotechnology that focus on cellular transplantation and the manufacture of artificial tissues. While the emphasis in this article is on cell migration in vertebrates, migration is equally important in invertebrates, plants and some single-cell organisms. Understanding migration presents a formidable intellectual challenge because it is the product of several complex, integrated processes that must be carefully regulated. Conceptually, the migrating cell is best viewed as a highly polarized entity with rapidly changing activities that are spatially segregated, particularly at the cell front and rear. For efficient migration to …